The industry has proposed many kinds of new mobility management technologies at present, and the essential idea is the subscriber identifier and locator separation technology. There is already a solution related to the Subscriber Identifier & Locator Separation Network (SILSN) in the related art, such as, realization based on the host such as the host identifier protocol (HIP) technology, and realization based on the network such as the locator and identifier separation (LISP) technology, and there are various associated technologies for supporting in each realization additionally. In these schemes, the Access Identifier (expressed as AID in this article) of terminal subscriber is not changed during the movement, and the Routing identifier (expressed as RID in this article) is assigned separately according to the terminal location to realize the routing and transmission of the data message.
FIG. 1 shows an architecture of an identifier and locator separation network (SILSN), using the realization based on the network. The network topology of the SILSN architecture is divided into the access network and the backbone network with the topology relation being not overlapped; the access network, which is responsible for the access of all terminals, is located at the edge of the backbone network, and the backbone network is responsible for the routing and transmission of the data message among the accessing terminals. In this network, the AID, as the subscriber identifier of the terminal, maintains unchanged all the time during the movement of the terminal; the RID is the Routing identifier assigned for the terminal by the network and used in the backbone network. It should be illustrated that there can be different names for different SILSN architectures, but the essences are the same.
In the SILSN architecture, the terminal can be one or more of a mobile terminal, a fixed terminal and a nomadic terminal, such as a mobile phone, a fixed telephone, a computer and a server, etc.
In the SILSN architecture, the access network is used for providing two-layer (the physical layer and the link layer) access means for the terminal, to maintain the physical access link between the terminal and the access service router (ASR).
In the SILSN architecture, the main network element of the backbone network includes the following elements:
An access service router (ASR) is an edge router of the backbone network, used for assigning an RID for a terminal, maintaining AID-RID mapping information of a terminal, registering and inquiring an AID-RID binding relation of a terminal at an identifier location register (ILR), and realizing routing and transmission of the data message, etc. The terminal must access to the backbone network through the ASR. The RID assigned for the terminal by the ASR includes address information of that ASR, or to say, pointing to that ASR. The ASR performs the tunnel encapsulation on the data message of the terminal by using the RID and RID of an opposite terminal after receiving the data message sent by the terminal, to send to the opposite terminal; and removes the RID tunnel encapsulation when receiving the data message sent to the terminal, and sends the data message to the terminal.
A common router (CR), is a core router of the backbone network, used for performing routing according to the RID in the data message, and transmitting the data message by taking the RID as the destination address.
The ILR is used for storing and maintaining the mapping information of the identifier and the Routing identifier of a home subscriber terminal, which is denoted as the AID-RID mapping information as well herein, processing the registration, deregistration and inquiry of the terminal location.
Alternatively, the backbone network can also include:
an internet service router (ISR), with an interface with the traditional IP network, the ASR and the ILR, used for realizing interconnection of an identifier and locator separation network and the traditional IP network.
It can be found that, in order to realize normal transmission of the message, the ASR needs to assign the RID for the terminal when the terminal is accessing, and needs to register the AID and RID binding of the subscriber at the ILR, to update the binding RID of the terminal in the ILR. In an example, the ASR maintains the information of the opposite terminal of the terminal (also can be called the connection information of the terminal and the communication opposite terminal, or the communication relation information of the terminal and the communication opposite terminal) for each terminal, including the corresponding relation information of the AID of the terminal and its communication opposite AID of the terminal, and also including the AID-RID mapping information of the terminal.
The identifier and locator separation network generally is designed to use the IP address as the identifier, for the transparent support of the application program and the terminal device, that is, what the socket of the application program is connected is still an IP address, and no change needs to be made. In fact, the meaning of the IP address is already not a routable IP address in common sense.
The identifier and locator separation network can solve a series of problems brought by the ambiguity of the IP address, but the access service router ASR needs to additionally use the RID to perform the tunnel encapsulation and decapsulation, and the tunnel encapsulation will increase the overhead of the backbone network.